Scientific Study

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component within a healthy diet. This systematic review and meta-analysis was conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomised controlled trials (RCTs). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September 2021. All RCTs studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analyses for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic, and funnel plots and Eggers test for outcomes with ≥10 strata. Quality assessment used the Health Canada Quality Appraisal tool, and the certainty of the evidence was assessed using GRADE. A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein cholesterol (HDL-C), LDL-C:HDL-C, and apolipoprotein B (ApoB) following nut consumption. The quality of evidence was ‘low’ for only 18 intervention studies. The certainty of the body of evidence for TC:HDL-C, LDL-C:HDL-C, and ApoB were ‘moderate’ due to inconsistency, for TG were ‘low’, and LDL-C and TC were ‘very low’ due to inconsistency and the likelihood of publication bias. The findings of this review provide evidence into a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction. https://doi.org/10.1016/j.advnut.2023.05.004